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Object Detecion - FOMO

This section describes how to train the FOMO mask detection model on the COCO MASK datasets. the implementations of FOMO mask detection model is based on the MobileNet V2 and MobileNet V3 (the actual neural network selected depends on the model profile you choose).

For more information about MobileNet, please refer to the paper MobileNets: Efficient Convolutional Neural Networks for Mobile Vision Applications.

Prepare Datasets​

SSCMA uses COCO_MASK Datasets by default to train the FOMO model, please refer to the following steps to complete the preparation of datasets.

  1. Please refer to Internet Datasets to download and unpack the dataset.

  2. Remember its folder path (e.g. datasets\mask) of the unpacked datasets, you may need to use this folder path later.

Choose a Configuration​

We will choose a appropriate configuration file depending on the type of training task we need to perform, which we have already introduced in Config, for a brief description of the functions, structure, and principles of the configuration file.

For the FOMO model example, we use fomo_mobnetv2_0.35_x8_abl_coco.py as the configuration file, which is located in the folder under the SSCMA root directory configs/fomo and its additionally inherits the default_runtime_det.py configuration file.

For beginners, we recommend to pay attention to the data_root and epochs parameters in this configuration file at first.

fomo_mobnetv2_0.35_x8_abl_coco.py 
_base_='../_base_/default_runtime_det.py'
default_scope='sscma'
custom_imports=dict(imports=['sscma'], allow_failed_imports=False)

num_classes=2
model=dict(type='Fomo',
           backbone=dict(type='mmdet.MobileNetV2', widen_factor=0.35, out_indices=(2,)),
           head=dict(type='FomoHead',
                     input_channels=[16],
                     num_classes=num_classes,
                     middle_channel=48,
                     act_cfg='ReLU6',
                     loss_cls=dict(type='BCEWithLogitsLoss',
                                   reduction='none',
                                   pos_weight=40),
                     loss_bg=dict(type='BCEWithLogitsLoss', reduction='none'),
           ),
)

# dataset settings
dataset_type='FomoDatasets'
data_root=''
height=96
width=96
batch_size=16
workers=1

train_pipeline=[
    dict(type='RandomResizedCrop',
         height=height,
         width=width,
         scale=(0.80, 1.2),
         p=1),
    dict(type='Rotate', limit=30),
    dict(type='RandomBrightnessContrast',
         brightness_limit=0.3,
         contrast_limit=0.3,
         p=0.5),
    dict(type='HorizontalFlip', p=0.5),
]
test_pipeline=[dict(type='Resize', height=height, width=width, p=1)]

train_dataloader=dict(
    batch_size=batch_size,
    num_workers=workers,
    persistent_workers=True,
    drop_last=False,
    collate_fn=dict(type='fomo_collate'),
    sampler=dict(type='DefaultSampler', shuffle=True, round_up=False),
    dataset=dict(type=dataset_type,
                 data_root=data_root,
                 ann_file='train/_annotations.coco.json',
                 img_prefix='train',
                 pipeline=train_pipeline),
)
val_dataloader=dict(
    batch_size=1,
    num_workers=1,
    persistent_workers=True,
    drop_last=False,
    collate_fn=dict(type='fomo_collate'),
    sampler=dict(type='DefaultSampler', shuffle=True, round_up=False),
    dataset=dict(type=dataset_type,
                 data_root=data_root,
                 ann_file='valid/_annotations.coco.json',
                 img_prefix='valid',
                 pipeline=test_pipeline))
test_dataloader=val_dataloader

# optimizer
lr=0.001
epochs=300
find_unused_parameters=True
optim_wrapper=dict(optimizer=dict(type='Adam', lr=lr, weight_decay=5e-4,eps=1e-7))

#evaluator
val_evaluator=dict(type='FomoMetric')
test_evaluator=val_evaluator
train_cfg=dict(by_epoch=True, max_epochs=70)

# learning policy
param_scheduler=[
    dict(type='LinearLR', begin=0, end=30, start_factor=0.001, by_epoch=False),  # warm-up
    dict(type='MultiStepLR',
         begin=1,
         end=500,
         milestones=[100, 200, 250],
         gamma=0.1,
         by_epoch=True)
]

Training Model​

Training the model requires using our previously configured SSCMA working environment, if you follow our Installation guide using Conda to install SSCMA in a virtual environment named sscma, please first make sure that you are currently in the virtual environment.

Then, in the SSCMA project root directory, we execute the following command to train a FOMO mask detection model.

python3 tools/train.py \
    configs/fomo/fomo_mobnetv2_0.35_x8_abl_coco.py \
    --cfg-options \
        data_root='datasets/mask' \
        epochs=50

During training, the model weights and related log information are saved to the path work_dirs/fomo_mobnetv2_0.35_x8_abl_coco by default, and you can use tools such as TensorBoard to monitor for training.

tensorboard --logdir work_dirs/fomo_mobnetv2_0.35_x8_abl_coco

After the training is completed, the path of the latest FOMO model weights file is saved in the work_dirs/fomo_mobnetv2_0.35_x8_abl_coco/last_checkpoint file. Please take care of the path of the weight file, as it is needed when converting the model to other formats.

tip

If you have a virtual environment configured but not activated, you can activate it with the following command.

conda activate sscma

Testing and Evaluation​

Testing​

After have finished training the FOMO model, you can specify specific weights and test the model using the following command.

python3 tools/inference.py \
    configs/fomo/fomo_mobnetv2_0.35_x8_abl_coco.py \
    "$(cat work_dirs/fomo_mobnetv2_0.35_x8_abl_coco/last_checkpoint)" \
    --cfg-options \
        data_root='datasets/mask'
tip

If you want a real-time preview while testing, you can append a parameter --show to the test command to show the predicted results. For more optional parameters, please refer to the source code tools/test.py.

Evaluation​

In order to further test and evaluate the model on a realistic edge computing device, you need to export the model. In the process of exporting the model, SSCMA will do some optimization on the model, such as model pruning, distillation, etc. You can refer to the Export section to learn more about how to export models.

Deployment​

After exporting the model, you can deploy the model to the edge computing device for testing and evaluation. You can refer to the Deploy section to learn more about how to deploy models.

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